Low-cost production of monodispersed timed-bioresorbable microspheres containing yttrium-90 (Y-90) will have a positive impact on radiation therapy in the United States and world wide. As more emphasis is given by the medical profession to short half-life, high energy, beta emitting isotopes (such as 7-90) to minimize major side effects of radiotherapy, Y- 90 has become the isotope of choice. As more therapeutic uses are being discovered for the short half-life isotope, it is necessary that the processing time involving isotopes be kept to an absolute minimum. A fully automated production process will ensure a fresh (non-decayed) supply of microsphere, will minimize or completely eliminate personnel exposure to radiation or radioactive materials, and will utilize the source isotopes such as strontium-90 (Sr-90) most efficiently and naturally in terms of material and radioisotope life. It is the objective of this proposed program to integrate demonstrated technologies and knowledge from national laboratories and private industries with XL Sci-Tech's timed-resorbable microsphere technology. Through process innovation, continuous low cost volume production of Y-90 microspheres will be achieved. Proposed commercial application: Microspheres containing isotopes such as Y-90, P-30 are ideal for direct intratumorial injection in treatment of cancers of liver, pancreas etc., and radiation synovectomy of rheumatoid arthritis.